Draft-gear.



1 Eatentedmar. 1,1910. .l

im v 1. m ,1 gw n 6 6 inf H M n J y w 6 a y 7 7 @5J G. A. LINDSTRM. DRAFT GEAR. A'PPLIOATION FILED AUG. 3. 190B.

C. A. LINDSTROM.

DRAFT GEAR.

APLIOATION IILED AUG.3,190B.

Patented Mar.1,'1910.

`2 SHEETS-SHEET 2.

.i E it clef-wem: i

[Befit -knownthat I, CHARLES A; LIN-D a L citzen of the United States, residing in .Pittsburg.l?'e11nsylvania, have inventedl certain Improvements in Draft-Gears,

'of'whieh the following is a specification.

One object of my invention is to provide a-.draftlgearhaving its arts so arranged that after 'a predetermined amount of strain has been applied to the draw bar, one niember ofthe device will be caused to turn relativelyto anotheragainst a relatively great frictional resistance.

-I furtherdesire to provide a draft gear of" the friction type which shall include a spring'so placed that after the device has been.. exposed to acertain predetermined stress so' as to compress the spring to a definite amount., one of its partsV shall be caused to screw into another against a relativeiy highfrictional resistance.

Another object of the invention is to provide a draft gear whose partsshall be so x constructed and'arranged that after a. spring has been compressed to a predetermined extent, -the pressure shall be automatically dividedbetween said spring and a pair of frictionallyoonnected members, one of whicl': i; free to turn relatively to the other. I A further object of the invention is to provide a draft lgear `with relatively large frictionalsurfaces so arranged that there'shall be a minimum ofinjurious recoil, when the gearis released, in order to avoid breaking o fifthe part-s'- 'A Ialso desireftoprovide a friction draft gear in'which the various parts are so constructed that `there will be practically no bursting pressure when it is compressed.

,Theseobjects and other advantageous ends I secure:` as hereinafter set forth, reference bei hadjftov the accompanying drawings, in whc if@ 1; ,n

Figure 1'-, e S'le'- eleratieaef .one format my inyeeonapat ofitheitfameuetk-btthe horizontal section taken; on. liane v 272, Fig,r l\`;F-ig.3',-is a horizontlseotion similar to that'of Fig. 2, but with part b frtghespring and the inside threaded -niemb'erjshown' in elevation; Fig. 4, is a transverse vertical scction on the line 4 4, Fig. 2; Figf, is'an end elevation of the rockers and their containinor casing as employed in the device illustrated in the previous figures; Fig. 6, is a horizontal section of a modified form of my invention,

Eff between 'y he: `plunger and Fig. 7 is a vertical section taken on the line 7 7, Fig. 6. l

In the above drawings .t-A represent the draft beams of the-car to which my invention is applied, and B represents the draw bar which is provided witha strap b held to it.- by rivets b as well as by its own-turned over ends. The draft beams have riveted or other wise attached to them suit-able sets of draft' lugs a and a', serving as abut-ments for two followers C and C', there being a filling block b2 interposed between the latterof these fol-V lowers and the strap o.

In the space between the followers is mounted a casing having two members D and D', of which the -first is held in any desired manner by the draft beams so that it cannot turn and is provided with internal threads having a 'relatively steep pitch. The part D is externally threaded so as to fit within thepart D and is internally flanged at one end; being constructed to be capable 'of fiatly engaging the adjacent face of the follower. The part D has interposed be'- tween it and the follower C a head el to which it is more or less loosely connectedby means of bolts d', and these latter serve to permit said parts to move toward and from one another to a limited extent. is formed with a. Vnumber of recesses, in the present instance six, which radiate from a central projection cl2, and each one of these' recesses contains a rocker Z3 engaging at' one end with the adjacent edge of the part D of the casing. A plate c 'engages the inner ends of the rockers, upon which it is supported lso as to be a short distance away from the vcentral projection cl2 .and it serves as an abutment for oneend of a pair of concentric cylindrical springs 'E and l l,' wl i`ose opposite ends engage a plunger c. The stem of this plunger engages the follower C and its head .is flanged so as to not only receive the two a, esule" tajine wayrririfeulg empresathsp'rifesah and at were which. :isi-engaged; by the @emaifnieea d2.' Y"As'r'hscon, however, as thepressr upon the spring exceeds a predetermined amount, this latter is compressed sufficiently to permit one end of the part D ofthe casing to Said head Ispeeiacation of Leiters-raient. Patented Mar. 1,1910. application fixed Augusta, 190s. serial no. 446,771.

ido

directly 'engage thefollower C. Any addiles tional load will nowforce said part D of the 'ca singinto the part D -or will tend .to cause p '.jsuch action, andI so 'design the threads of the partsD and D. that their relative 'movement isaccompanied by great. friction. "1` his.

. actionis due tothe retarding-f1'ictono'f-the 'faces of the partsD and e-agamst the face ofthe follower C, Finally when the pullor -push onthe draw bar has been still further .increased so'that the artDj has bee'nscrewed into the part D su ciently tounearly com--A press the spring to the limit, theends of the;

' casing D will engage the'end of the partv D `j' and the pull or Owing to the 'push is transmitted 'directlyl to thefollow'ers' looseV connection between the' part D. of the casing-andthe head d, pressurefromv the springs upon the plate e causes fthe rockers d3 to ajct as levers and move the -partD -in vthe opposite'direction toward the follower C, therebytaking up any clearance in the thread and insuring that ywhen the -follower C has been forced againstV the part` D, the' pressure from the draw bar on the springs andv on the part D acts in the same direction on4 the thread.

:Wit-h the parts arranged as shown,` is

zobvious that any light or normal pull on the x drawbar is' transmitted tothe frame 'of the. 30

vcar solely throughthe springs, while any abnormal strain is divided between the springs and the friction devices provided by the two part-casing, being restricted 'also by y the'frictlon'between the-faces of the parts c and D and the face of the follower C. By

'permitting one part of this casing' to turn e relatively to the other,Inot 01115I avoid the transmission of shocks but also render possible' the transmission of abnormal loads without danger of injury to any of the (parte.

Moreover the 'means whereby vthese en s are attaln'ed are relatively uncomplicated and -are not likely to require attention orA beeasily 4put out of order.

In some instances, I may, if desired, omit 'therockers from the construction without departing frolnthe'V main featuresthereof,

- enite amount,`the` part D of the casing and in this easel arrange the' parts as shown in Figs. G'and 7 ,.where'the 'internally thread-4 ed part I)2 of the casing bears-upon theface of Athe casing. As' beforea pull less than a engagesthe follower C, and thereafter the force transmitted' from-the draw bar lto the' v,stressedfto a predetermined extent.

l frame of the cariis'. th'e'two springs and the friction.' device" formed byV the '.two part fca'singg-Jand i's resisted 'by the friction between the facesof'the plunger e,

the part'D and the'jface'of th'efollower C.V

` It is obvious that while in my preferred.

ay be so changed that the ing land-theinsidlepa'rt' D is caused-to turn, ,the construction insde'pa-rt D is held by one' of the follower lates-from revolving' and the outside parts I) or 'Dzzareallowed to revolve..- It4 is also ev'id'ent thatth'e type-of threads used 'maybe' either bastardorsquareor any other 'shape .ins'tead'of thevshape shown in the drawings and that the pitch of the threads may 'be madejt vlany deslred angle-1 Itis also' ob vio'us that numerous lother' changes may be made in? details without 'departing from 'my invention;

1.A 'The comblnation'oftwo followers, a series of rockers Vmounted to receive pressure therefrom, aspring acting at. one' end upon the rockers, anda two part casing between' thefollowers, one part-of the casingbeing Elaced to act upon the rockers and the other 'eing free to turn4 .relatively to the "other partwhen pressureis exertedupon it.

2. The combinationjin a draft gear; of two followers, a casing having two parts threaded together, a ,spring mounted between the followers, and rockers connecting the spring and one part of the casing;

3 AQ draft g'ear interposed `between the draw bar and the frame of a car, the-'same consisting of a spring, two members free to turn relatiVeIy'to'eaCh other when under pressure,- and ay series-of rockers for transmitting pressure to Vonel of said members and to the spring after sa'id spring has been stressed to a' predetermined extent.

4. The combination with the frame of a car, and ndraw bar, of two'follo'wers interposed between'jsaid' parts, a head having mounted on 1t a senos-of rockers and being "placed to bear'upon one ofl the followers, a 'two part casing loosely' connected to 'said' head and having its parts threaded oneinto the other, one' part bearing upon' the rockers, n 'spring acting at one end upon `the rrockers 'and'at its other end acting upon one of theifollowers, 'so that 'one part movesrelatively tothe other after the spring has'been In testimonyrwhereof, I have slgned name to this specification, in the presence of two subscribing witnesses.`

CHARLESALLINDSTRM; 

